This application relates to devices, techniques, and materials for forming, storing, reacting, and transporting fuels and other materials.
Gaseous substances such as oxygen, nitrogen, carbon dioxide and fuels such as hydrogen and methane are more difficult and costly to store and transport than denser liquids or solids. For example, pressurizing hydrogen and/or methane can require sizeable capital expenditures, large energy expenditures for compression and/or to produce cryogenic liquids and attendant production of greenhouse gases, and high operating costs. Further, the pressure boosting equipment for transporting the pressurized hydrogen and/or methane through pipelines often incur costly maintenance and repair costs.
In addition to the compressed-gas fuel form, hydrogen can be converted to cryogenic liquid or slush for storage. Liquid hydrogen is generally stored at −252° C. (−423° F.) at atmospheric pressure and often transported through under insulated delivery lines, parts of which can be damaged due to atmospheric water vapor condensation and freezing. Storage and transport of cryogenic methane faces similar costs.
Moreover, the high cost of storage and transport for hydrogen and methane is met with low energy density. For example, a gallon of cryogenic liquid methane at −162° C. (−260° F.) provides an energy density of 89,000 BTU/gal, about 28% less than a gallon of gasoline. Liquid hydrogen at −252° C. provides only about 29,700 BTU/gal, about 76% less than gasoline.
Like reference symbols and designations in the various drawings indicate like elements.